A recent thread by @Alvin got me thinking more about this. I have always tended toward insomnia all through out my years of ME. I often wonder whether the differences here are a subgroup difference. Are there any clues to the reasons why some MEs have insomnia others have somnolence. Do autoimmune diseases cause one or the other mainly? Why do some get insomnia and others not? There must be differences in metabolites? Anyone have any ideas?